1. Field of the Invention
The present invention relates to a surgical implant, more particularly, for an intervertebral stabilizer, formed from an intra-osseous rod. The rod has one end implanted into the bone and another end forming an extra-osseous head for retaining at least one flexible ligament.
2. The Prior Art
In an intervertebral stabilizer of the type described in French patent application 89 01445, the implants are anchored by the intra-osseous rod in the vertebrae of the area to be treated. The extra-osseous head forms an attachment point for the ends of a flexible ligament which is thus freely retained between two successive vertebrae.
Such stabilizers have the advantage of correcting a large number of anatomical defects of the spine without impeding the natural bending and twisting movements of the trunk of the patient.
However, the repetition of these movements can, in certain cases, lead to progressive wear of the ligaments, due to excessive friction with the rough surface of the vertebrae or a second ligament mounted on the extra-osseous head of the same implant. As such wear inevitably modifies the initial tension of the ligaments or snaps the ligaments, it is necessary for the patient to undergo further surgery to repair the damaged intervertebral stabilizer.